Exterior and Prefab Building Type Designed by Phoenix-based ASUL—which stands for adaptable system for universal living—and CSCP Consult in Savannah, Georgia, this is not a full-fledged home but rather an accessory dwelling unit, known as an ADU. Its 16-foot by 20-foot interior is cozy and practical, inspired by the midcentury main house adjacent to the building, which is used as an office, library, and study. The ADU rests on 6-foot stilts to comply with FEMA flood zone requirements.  Photo 3 of 4 in 4 Innovative Prefab Homes in Georgia